Add implementation of MultipartFormData streaming encoder (#200)

builtins/web/fetch/request-response.cpp

@@ -1,6 +1,8 @@
 #include "request-response.h"
 
 #include "../blob.h"
+#include "../form-data/form-data.h"
+#include "../form-data/form-data-encoder.h"
 #include "../streams/native-stream-source.h"
 #include "../streams/transform-stream.h"
 #include "../url.h"
@@ -17,6 +19,7 @@
 #include "js/Conversions.h"
 #include "js/JSON.h"
 #include "js/Stream.h"
+#include "mozilla/ResultVariant.h"
 #include <algorithm>
 #include <iostream>
 #include <vector>
@@ -27,8 +30,6 @@
 #include "js/experimental/TypedData.h"
 #pragma clang diagnostic pop
 
-using builtins::web::blob::Blob;
-
 namespace builtins::web::streams {
 
 bool NativeStreamSource::stream_is_body(JSContext *cx, JS::HandleObject stream) {
@@ -41,6 +42,12 @@ bool NativeStreamSource::stream_is_body(JSContext *cx, JS::HandleObject stream)
 
 namespace builtins::web::fetch {
 
+using blob::Blob;
+using form_data::FormData;
+using form_data::MultipartFormData;
+
+using namespace std::literals;
+
 static api::Engine *ENGINE;
 
 bool error_stream_controller_with_pending_exception(JSContext *cx, HandleObject stream) {
@@ -286,19 +293,19 @@ bool RequestOrResponse::extract_body(JSContext *cx, JS::HandleObject self,
   MOZ_ASSERT(!has_body(self));
   MOZ_ASSERT(!body_val.isNullOrUndefined());
 
-  const char *content_type = nullptr;
+  string_view content_type;
   mozilla::Maybe<size_t> content_length;
 
-  // We currently support five types of body inputs:
+  // We support all types of body inputs required by the spec:
   // - byte sequence
   // - buffer source
   // - Blob
+  // - FormData
   // - USV strings
   // - URLSearchParams
   // - ReadableStream
   // After the other other options are checked explicitly, all other inputs are
   // encoded to a UTF8 string to be treated as a USV string.
-  // TODO: Support the other possible inputs to Body.
 
   JS::RootedObject body_obj(cx, body_val.isObject() ? &body_val.toObject() : nullptr);
   host_api::HostString host_type_str;
@@ -318,8 +325,33 @@ bool RequestOrResponse::extract_body(JSContext *cx, JS::HandleObject self,
     if (JS::GetStringLength(type_str) > 0) {
       host_type_str = core::encode(cx, type_str);
       MOZ_ASSERT(host_type_str);
-      content_type = host_type_str.ptr.get();
+      content_type = host_type_str;
+    }
+  } else if (FormData::is_instance(body_obj)) {
+    RootedObject encoder(cx, MultipartFormData::create(cx, body_obj));
+    if (!encoder) {
+      return false;
+    }
+
+    RootedObject stream(cx, MultipartFormData::encode_stream(cx, encoder));
+    if (!stream) {
+      return false;
     }
+
+    auto boundary = MultipartFormData::boundary(encoder);
+    auto type = "multipart/form-data; boundary=" + boundary;
+    host_type_str = string_view(type);
+
+    auto length = MultipartFormData::query_length(cx, encoder);
+    if (length.isErr()) {
+      return false;
+    }
+
+    content_length = mozilla::Some(length.unwrap());
+    content_type = host_type_str;
+
+    RootedValue stream_val(cx, JS::ObjectValue(*stream));
+    JS_SetReservedSlot(self, static_cast<uint32_t>(RequestOrResponse::Slots::BodyStream), stream_val);
   } else if (body_obj && JS::IsReadableStream(body_obj)) {
     if (RequestOrResponse::body_unusable(cx, body_obj)) {
       return api::throw_error(cx, FetchErrors::BodyStreamUnusable);
@@ -364,15 +396,15 @@ bool RequestOrResponse::extract_body(JSContext *cx, JS::HandleObject self,
       auto slice = url::URLSearchParams::serialize(cx, body_obj);
       buf = (char *)slice.data;
       length = slice.len;
-      content_type = "application/x-www-form-urlencoded;charset=UTF-8";
+      content_type = "application/x-www-form-urlencoded;charset=UTF-8"sv;
     } else {
       auto text = core::encode(cx, body_val);
       if (!text.ptr) {
         return false;
       }
       buf = text.ptr.release();
       length = text.len;
-      content_type = "text/plain;charset=UTF-8";
+      content_type = "text/plain;charset=UTF-8"sv;
     }
 
     if (!buffer) {
@@ -413,7 +445,7 @@ bool RequestOrResponse::extract_body(JSContext *cx, JS::HandleObject self,
     content_length.emplace(length);
   }
 
-  if (content_type || content_length.isSome()) {
+  if (!content_type.empty() || content_length.isSome()) {
     JS::RootedObject headers(cx, RequestOrResponse::headers(cx, self));
     if (!headers) {
       return false;
@@ -427,7 +459,7 @@ bool RequestOrResponse::extract_body(JSContext *cx, JS::HandleObject self,
     }
 
     // Step 36.3 of Request constructor / 8.4 of Response constructor.
-    if (content_type &&
+    if (!content_type.empty() &&
         !Headers::set_valid_if_undefined(cx, headers, "Content-Type", content_type)) {
       return false;
     }

builtins/web/file.cpp

@@ -75,6 +75,11 @@ bool File::lastModified_get(JSContext *cx, unsigned argc, JS::Value *vp) {
   return true;
 }
 
+JSString *File::name(JSObject *self) {
+  MOZ_ASSERT(is_instance(self));
+  return JS::GetReservedSlot(self, static_cast<size_t>(Slots::Name)).toString();
+}
+
 // https://w3c.github.io/FileAPI/#file-constructor
 bool File::init(JSContext *cx, HandleObject self, HandleValue fileBits, HandleValue fileName,
                 HandleValue opts) {

builtins/web/file.h

@@ -23,6 +23,8 @@ class File : public BuiltinImpl<File> {
   static const JSFunctionSpec methods[];
   static const JSPropertySpec properties[];
 
+  static JSString *name(JSObject *self);
+
   static JSObject *create(JSContext *cx, HandleValue fileBits, HandleValue fileName, HandleValue opts);
   static bool init(JSContext *cx, HandleObject self, HandleValue fileBits, HandleValue fileName, HandleValue opts);
   static bool init_class(JSContext *cx, HandleObject global);